KOSPI Roars Back 3.8% to 6,598 as Foreign Buyers Erase a 5.1% Plunge

South Korea’s benchmark KOSPI closed 3.8% higher at 6,598, completing a round trip from a selloff that had knocked the index down 5.1% to 6,257 only days earlier. Foreign investors drove the advance, buying a net 1.4 trillion won of Seoul-listed shares, and the surge was forceful enough to trigger buy-side sidecars — the program-trading curbs more often associated with crashes — on both the main board and the tech-heavy KOSDAQ, which finished 2.4% higher.

From 6,257 Back Above Water in Two Sessions

The rebound unfolded in stages. After the 5.1% slide dragged the KOSPI to 6,257, the index first clawed back 1.6% in a session that saw the KOSDAQ jump 5.9%. The follow-through came with the 3.8% surge to 6,598 — a close that put the benchmark roughly back to, and by a small margin above, where it stood before the drop began. In percentage terms, the entire selloff was erased.

The final leg started strong and stayed strong. The index opened with gains in the 3–4% range, lifted by overnight strength in U.S. markets, and held most of that advance into the close rather than fading, with intraday gains at one point topping 4%.

A 1.4 Trillion Won Vote From Foreign Money

The 1.4 trillion won in net foreign purchases marks the flow story behind the price story. Korean equities remain unusually sensitive to offshore positioning, and the pattern across this stretch — heavy selling into the plunge, aggressive buying on the way back — is consistent with global funds treating the drop as a valuation reset rather than the start of a downtrend. The KOSDAQ’s participation, up 2.4% alongside the larger caps, suggests the buying was broad rather than concentrated in a handful of index heavyweights.

Curbs Designed for Panic, Triggered by a Rally

Sidecars pause program trading for several minutes when futures prices move sharply in one direction, and they fire on the upside as well as the downside. The KOSPI’s buy sidecar activated as the index ran up more than 4%; the KOSDAQ’s kicked in during a session in which that market swung from early losses to a gain of more than 3%. Upside sidecars are rare, and their appearance on both exchanges within the same rebound underlines how compressed the buying was — demand arriving faster than the market’s plumbing is calibrated to absorb.

A Market Moving in Full-Percentage Strides

The wider takeaway is the amplitude, not the direction. Within a handful of sessions the KOSPI posted a 5.1% loss, a 1.6% gain, and a 3.8% gain, while the KOSDAQ logged single-day moves of 5.9% and 2.4%. Swings of that size in both directions point to a market where conviction is thin and flows dominate: gains built on a single burst of foreign buying can unwind on the next shift in U.S. sentiment. The recovery is complete on the scoreboard at 6,598; whether it is durable depends on whether the foreign bid persists once the rebound premium is gone.